Abstract: For the generation of multiple-energy X-ray radiation, an X-ray tube (10) for generating multiple-energy X-ray radiation includes an anode (12) and a filter (14). At least a first (16) and a second focal spot position (18) are offset from each other in an offset direction (20) transverse to an X-ray radiation projection direction. The filter includes a first plurality (22) of first portions (24) with first filtering characteristics for X-ray radiation and a second plurality (26) of second portions (28) with second filtering characteristics for X-ray radiation. The filter is a directional filter adapted in a such a way that at least a first X-ray beam (30) emanating from the first focal spot position at least partly passes through the filter unit via the first portions, and a second X-ray beam (32) emanating from the second focal spot position passes obliquely through the first and the second portions when passing through the filter unit.

Abstract: The present invention relates to determining changes in the X-ray emission yield of an X-ray tube, in particular determining dose degradation. In order to provide determination of such changes, an X-ray source is provided comprising a cathode, an anode; and at least one X-ray sensor (16). The cathode emits electrons towards the anode and the anode comprises a target area on which the electrons impinge, generating X-ray radiation. An X-ray barrier (24) is provided with an aperture (26) for forming an emitting X-ray beam from the X-ray radiation, wherein the emitting X-ray beam has a beam formation (30) with a central axis. The at least one X-ray sensor is arranged within the beam formation and measures the X-ray intensity for a specific direction of X-ray emission with an angle with respect to the central axis. The at least one X-ray sensor can be positioned inside the beam formation (30), but outside the “actual field of view” (40) as determined by a diaphragm (36).

Abstract: The present invention relates to filtering of X-ray radiation generated at multiple focal spots. For the generation of multiple-energy X-ray radiation, an X-ray tube (10) for generating multiple-energy X-ray radiation is provided that comprises an anode (12) and a filter unit (14). The anode comprises at least a first (16) and a second focal spot position (18), which are offset from each other in an offset direction (20) transverse to an X-ray radiation projection direction.

Abstract: An electron emitter (1) and an X-ray tube (100) comprising such electron emitter (1) are presented. The electron emitter (1) comprises a cathode (3) and an anode (5) wherein the cathode (3) comprises an electron emission pattern (9) of a plurality of local areas (11) spaced apart from each other, each area being adapted for locally emitting electrons via field emission upon application of an electrical field between the cathode (3) and the anode (5). Electron beams (15) emitted from the local areas (11) may generate several X-ray source intensity maxima in a specific geometric pattern. An apparent loss in spatial resolution due to overlapping images on a detector can be corrected by using specific intensity patterns for the X-ray source (100) and by applying dedicated decoding algorithms on the acquired image such as coded source imaging (CSI).